(1) Field of the Invention
The present invention relates to a cosmetic composition, more specifically to a cosmetic composition which is prepared by using iron oxide particles of red iron oxide and the like as a coloring material for liquid cosmetics and which is suitable for eyeliners and excellent in a dispersibility and an aging stability.
(2) Description of Related Art
From the past up to the present time, coloring materials for cosmetics have so far been restricted in use from the viewpoint of a safety. In particular, coloring materials which can be used for cosmetics for eye makeup such as eyeliners are restricted. In general, coloring materials are classified into dyes and pigments, and coloring matters are deposited in a case of the dyes, so that the pigments are being increased recently in use. Among them, inorganic pigments which can be used at ease in terms of a safety are usually used.
However, the inorganic pigments have involved the problem that in a case of, for example, iron oxide, it has a high specific gravity and a large primary particle diameter and that it settles down for short time in a low viscous composition to cause color separation.
Known as patent documents in which iron oxide is used as a pigment for liquid cosmetics are, for example, 1) eye makeup cosmetics comprising aqueous dispersions which contain (A) an iron base inorganic pigment, (B) an anionic polymer compound and (C) at least one chelating agent selected from ethylenediaminehyroxyethyl triacetate and salts thereof and which have a viscosity of 3 to 300 cps (centipoise) at a temperature of 25° C. (refer to, for example, Japanese Patent Publication No. 1992-66447), 2) pigment dispersions for cosmetics containing black iron oxide, red iron oxide and Prussian blue, and eyeliners prepared by charging a pen type vessel with the above dispersion (refer to, for example, Japanese Patent Application Laid-Open No. 2003-23614), 3) pigment dispersions for cosmetics containing poly-γ-L-glutamic acid and/or salts thereof, black iron oxide, red iron oxide and Prussian blue, and eyeliners prepared by charging a pen type vessel with the above dispersion (refer to, for example, Japanese Patent Application Laid-Open No. 2012-1503), and 4) pigment dispersions for cosmetics prepared by using black iron oxide in combination with a small amount of red iron oxide and blending additionally α-olefin sulfonic acid salt, and eyeliners prepared by charging a pen type vessel with the above dispersion (refer to, for example, Japanese Patent Application Laid-Open No. 2012-184181).
However, in the compositions for cosmetics described in the patent documents described above, whereas the effects can be exerted in a part of the pen type specifications thereof, the bulk substances settle down and are separated, and therefore involved therein is the problem that when the pen type structure is changed, it is difficult to exert the effects thereof.
In general, brown color base compositions for eyeliners are toned by adding carbon black to red iron oxide, but the existing situation is that because of a high specific gravity and a large particle diameter of red iron oxide, problems such as color separation and the like are involved therein.